user
Explain why the following code won't execute properly.
`foo = bar(1, 2, 3)
print(foo)`


assistant
This code won't execute properly because 'bar' is not defined as a function within the code. The code is trying to call a function called 'bar' that does not exist, resulting in an error. In order to fix this, the code must include a function definition for 'bar', which contains instructions for what the function should do when it is called.